Project Summary/Abstract At least one quarter of the 18 million persons in the US with intellectual and developmental disabilities engage in self-injurious behavior (SIB), which can result in injuries, disfigurement, and loss of function (e.g., blindness). In most cases, SIB is maintained by social reinforcement (e.g., attention). SIB that persists in the absence of social reinforcement has been referred to as automatically reinforced SIB (ASIB), based on the supposition that the behavior itself produces some type of biological reinforcement. The current standard of care approach to treatment for ASIB includes two phases: a Pre-Treatment Assessment (a Competing Stimulus Assessment to identify stimuli associated with reductions in ASIB), followed by treatment where competing stimuli are delivered on a noncontingent reinforcement (NCR) schedule. Our NICHD- supported research to date has identified subtypes of ASIB that vary greatly in terms of their responsiveness to these treatments. Subtypes are based on results of standardized assessment conditions: Subtype 1 varies inversely with the level of stimulation across conditions; Subtype 2 is invariant; and Subtype 3 is characterized by self-restraint, a self-limiting behavior that occurs to avoid ASIB, but also impairs adaptive functioning. Treatments using NCR with competing stimuli alone are effective in over 82% of cases with Subtype 1, but in only 7% of cases with Subtype 2 or 3, necessitating restraint or protective equipment to sufficiently reduce ASIB. The identification of subtypes has revealed the urgent need for more effective interventions for the treatment-resistant subtypes. Fortunately, our research (R01 HD076653) has also led to several recent discoveries that provide the conceptual and empirical basis for a new Intensified Approach to treatment targeting the most treatment-resistant subtypes (Subtype 2 and 3 ASIB). The proposed treatment approach is based on the same principles as the current Standard of Care Approach (Matching Law and reinforcer competition), but employs novel methods to more effectively compete with reinforcement maintaining Subtype 2 and 3 ASIB, and to address self-restraint for Subtype 3. The proposed Intensified Approach to treatment includes three phases: 1) Pre-Treatment Assessments will identify competing stimuli, tasks, and self-control devices that reduce ASIB; 2) Intensive Training to strengthen skills needed to fully access available reinforcement, and replace debilitating self-restraint; and 3) Combination Treatment using NCR to deliver, and differential reinforcement for engagement with: multiple competing stimuli, competing tasks, and alternative self-control devices (for Subtype 3). Combination Treatment is designed to greatly increase the amount and vary the sources of alternative reinforcement. Aim 1 is to identify and establish competing stimuli, competing tasks, and self-control devices (Subtype 3 ASIB). Aim 2 is to employ a randomized crossover design to demonstrate the effectiveness of Combination Treatment (developed using the Intensified Approach), relative to NCR with competing stimuli alone (developed using the current Standard of Care Approach) for reducing ASIB and self-restraint.